PCA9673BQ: Remote 16-bit I/O expander for Fm+ I2C-bus with interrupt and reset

The PCA9673 provides general purpose remote I/O expansion for most microcontroller families via the two-line bidirectional bus (I²C-bus) and is a part of the Fast-mode Plus family.

The PCA9673 is a drop in upgrade for the PCF8575 providing higher Fast-mode Plus (Fm+) I²C-bus speeds (1 MHz versus 400 kHz) so that the output can support PWM dimming of LEDs, higher I²C-bus drive (30 mA versus 3 mA) so that many more devices can be on the bus without the need for bus buffers, higher total package sink capacity (400 mA versus 100 mA) that supports having all 25 mA LEDs on at the same time and more device addresses (16 versus 8) are available to allow many more devices on the bus without address conflicts.

The difference between the PCA9673 and the PCF8575 is that the A2 address pin is replaced by a RESET input on the PCA9673.

The device consists of a 16-bit quasi-bidirectional port and an I²C-bus interface. The PCA9673 has a low current consumption and includes latched outputs with 25 mA high current drive capability for directly driving LEDs.

It also possesses an interrupt line (INT) which can be connected to the interrupt logic of the microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I²C-bus.

The internal Power-On Reset (POR), hardware reset pin (RESET) or software reset sequence initializes the I/Os as inputs.

PCA9673BQ: Product Block Diagram
Outline 3d SOT815-1
Data Sheets (1)
Name/DescriptionModified Date
Remote 16-bit I/O expander for Fm+ I2C-bus with interrupt and reset (REV 2.0) PDF (284.0 kB) PCA967329 Sep 2011
Application Notes (3)
Name/DescriptionModified Date
Driving stepper motors using NXP® I2C-bus GPIO expanders (REV 2.0) PDF (275.0 kB) AN1081424 Oct 2011
PCA9500/PCA9501 provides simple card maintenance and control using I²C-bus (REV 1.0) PDF (90.0 kB) AN25623 Mar 2009
Level shifting techniques in I2C-bus design (REV 1.0) PDF (52.0 kB) AN1044120 Jun 2007
Users Guides (4)
Name/DescriptionModified Date
I2C-bus specification and user manual (REV 6.0) PDF (1.4 MB) UM1020428 Apr 2014
I2C-bus specification and user manual (REV 5.0) PDF (1.6 MB) UM10204_JA03 Apr 2013
PCA9698 demonstration board OM6281 (REV 1.0) PDF (558.0 kB) UM1026726 Sep 2008
I2C Demonstration Board 2005-1 Quick Start Guide (REV 1.0) PDF (261.0 kB) UM1020613 Jun 2006
Brochures (3)
Name/DescriptionModified Date
NXP® I2C-bus solutions 2014: Smart, simple solutions for the 12 most common design concerns (REV 1.0) PDF (3.5 MB) 7501754001 Aug 2014
Versatile, easy-to-use GPIO expanders; NXP® 4/8/16-bit I2C/SMBus GPIO expanders PCA9536/54/54A/55 (REV 1.0) PDF (319.0 kB) 7501653501 Aug 2008
Create smarter, more efficient white goods; An industry-leading portfolio of cost-effective, power-saving solutions for... (REV 1.0) PDF (1.1 MB) 7501654301 Jun 2008
Package Information (1)
Name/DescriptionModified Date
plastic dual in-line compatible thermal enhanced very thin quad flat package; no leads; 24 terminals; body 3.5 x 5.5 x... (REV 1.0) PDF (195.0 kB) SOT815-108 Feb 2016
Packing (1)
Name/DescriptionModified Date
DHVQFN24; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or... (REV 4.0) PDF (205.0 kB) SOT815-1_11819 Apr 2013
Ordering Information
ProductStatusStatusBudgetary Price excluding tax(US$)Package Type and Termination CountGPIOsQualification Tier
PCA9673BQEnd of Life